Use standalone navigation module with ArduCopter


I’m working on a project where we will utilize a complete standalone navigation module (attitude, position, velocity etc etc) and feed that information in to use in its attitude and position control. This data will be at 100Hz through the serial connection. What would be the best way to move forward on this? As I am not that familiar with the relatively low-level part of the ardupilot code, it currently seems to be a bit unclear where the best place to make this change would be. The onboard EKF will still be running in the background in case the serial connection drops.

All tips will be appreciated!